Sectional carbon electrode



Filed May 31, 1951 INVENTOR. Lee/77cm J. M 6407 BY @firQ- 9MP ATTORNEY.

Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE SECTIONAL CARBONELECTRODE Leeman J. McCarty, Kalamazoo, Mich.

Application-May a, 1951, Serial-No. 229,129

7 .Claims.

This invention relates to improvements in sectional carbon electrode.

The main objects of this invention are:

First, to provide a sectional carbon electrode in which thesections areeffectively joined and one in which the joint is maintained or is notdisrupted or broken during use.

Second,to .provide a sectional carbon electrode having these advantageswhich is simple and economical toproduce.

Objectsrelating .to details and'economies of the invention will appearfrom the description to follow. The invention is pointed out in theclaims.

A preferred embodiment of the invention is illustrated in theaccompanying drawings, in

which I Fig. 1 is an enlarged'fragmentary sideelevational view of :asectional carbon electrode embodying my invention partially inlongitudinal section, the thickness of the adhesive in the joint beingshown greatly exaggerated.

Fig. 2-is a fragmentary side view looking from the top of Fig. 1.

Fig. 3 is an enlarged transverse section on the broken line 3-3 of Fig.1.

Fig. 4 is a fragmentary side elevational view of one of the sectionspartially in longitudinal section to show the socket at one end and thedowel at the other.

Fig. 5 is a fragmentary longitudinal section of a modified form orembodiment of my invention taken on a line corresponding to line 5-5 ofFig. 6.

Fig. 6 is an enlarged transverse section on a line corresponding to lineB6 of Fig. 5.

Carbon electrodes embodying my invention are particularly desirable foruse in moving picture projecting machines and the like. Attempts havebeen made to utilize the pieces of partially used carbon electrodes byjoining to other sections but the results have not been entirelysatisfactory, owing to the fact that the joints were broken or rupturedin use. The applicants joint remains intact and effective in use.

Referring to the drawing, the carbon electrode illustrated comprises thesections 1 and 2 which consist of relatively soft carbon cores 3, aharder or denser surrounding carbon 4 and a metal sheath 5. This type ofcarbon electrode is old in the art. The section is provided with asocket 6 while the section 2 has a coacting dowel 1 telescopinglyengaged in the socket. In practice, these parts are a close fit but Ihave illustrated substantial clearance in order to illustrate theadhesivet which is employed to bond the telescoping parts together.There issubstantial variation in .the manufacture of these telescopingparts but .as stated, they desirablyhave a provided with a vent 1'4which .opens'to thebottom of the socket and through the sheath and inthe embodiment illustrated through the'sleeve although the sleeve israrely of 'such a fit as to render the vent opening thereto necessaryasthe gases may escape 'atthe ends 'of "the'sleeve. In use, gasesaccumulate in "the joint which applicant believes is largely 'due to theburning of the adhesive, the accumulation of gases frequently being suchthat there is an *explosive action which ruptures or breaks the joint.Applicants vent allows the gases to escape and the joint is not rupturedor broken when-the electrodes are in use. This-enablestheeffe'ctive'joining of sections and the full use thereof.

Fig. 4 is an illustration of one of the carbon sections of theembodiments of Figs. 1 to 4. The section is formed with a socket 6 atone end and a dowel I at the other. In the embodiment shown in Figs. 5and 6 the sections I5 are provided with sockets H5 at both ends, onlyone end being illustrated. The dowel I! is a separate carbon electrodeelement and telescopes with the adjacent sockets as is illustrated inFig. 5. This dowel I! is provided with a longitudinal groove I8extending from end to end thereof and therefore opening to the bottomsof the sockets.

The adhesive is indicated at l9 and again it is pointed out that it isshown in an exaggerated thickness for convenience in illustration. Inthis embodiment the venting opening is between the ends of the sections20, the venting groove opening between the sections. The sections arenot in such close abutting relation as to prevent this venting betweenthe ends thereof. This embodiment provides a joint which is also verysecure and not likely to become ruptured or broken in use as the resultof gas accumulating in the joint which as pointed out very frequenlyresults in the breaking or rupturing of the joints in sectional carbonelectrodes.

Applicant has illustrated and described two practical embodiments of hisinvention. He has not attempted to illustrate or describe otherembodiments or adaptations which he contemplates as it is believed thatthis disclosure will enable those skilled in the art to embody or adapthis invention as may be desired.

Having' thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A carbon electrode comprising sections having metal sheaths, densebodies adjacent the sheaths and soft cores within the bodies, onesection having a socket in its body and the other a dowel on its bodytelescopingly engaged with the socket, the joint including a bondingadhesive having the property of gasiiying at high temperature for thetelescoping parts of the sections, and a coupling sleeve embracing thesections at the joint to reinforce the same and provide an electricalconnection fer the sheaths of i the sections, the section having thesocket having a vent opening formed through its sheath and body to thebottom of the socket to permit the escape of gas from the socket.

2. A'carbon electrode comprising sections having metal sheaths, densebodies adjacent the sheaths and soft cores within the bodies, onesection having a socket in its body and the other a dowel on the bodytelescopingly engaged with the socket, the joint including a bondingadhesive having the property of gasifying at high temperature for thetelescoping parts of the 7 sections, the section having the sockethaving a vent opening formed through its sheath and body to the bottomof the socket to permit the escape of gas from the socket.

3. A sectional carbon electrode, one section having a socket and theother a dowel telescopingly engaged with the socket, the joint includinga bonding adhesive having the property of gasifying at high temperaturefor the telescoping parts of the sections, the section having the sockethaving a vent opening to the socket to permit the escape of gas from thesocket.

4. A carbon electrode comprising sections having metal sheaths andhaving aligned sockets in their meeting ends, a carbon connecting dowelfor said sections telescoped within said sockets, said dowel having alongitudinal peripheral groove extending from end to end thereof, thejoint including a bonding adhesive having the property of gasifying athigh temperature for the telescoping parts, said groove constituting avent extending across the adjacent ends of the sections, and a metalcoupling sleeve embracing the joint of said sections to reinforce thesame and provide an electrical connection for the sheaths.

5. A carbon electrode comprising sections having metal sheaths andhaving aligned sockets in their meeting ends, and a carbon connectingdowel for said sections telescoped within said sockets, said dowelhaving a longitudinal peripheral groove extending from end to endthereof, the joint including a bonding adhesive having the property ofgasifying at high temperature for the telescoping parts, said grooveconstituting a vent extending across the adjacent ends of the sections.

6. A sectional carbon electrode, the sections having aligned sockets intheir meeting ends, and a carbon connecting dowel for said sectionstelescoped within said sockets, said dowel having a longitudinalperipheral vent groove opening between the abutting ends of thesections, the joint including a bonding adhesive having the property ofgasifying at high temperature for the telescoping parts.

7. A carbon electrode comprising a plurality of sections having doweland socket telescoping engagement, the joint including a bondingadhesive having the property of gasifying at high temperature for thetelescoping parts, the bottom of the socket being vented to theatmosphere to permit the escape of gas from the socket.

LEEMAN J. MCCARTY.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,120,243 Droll June 14, 1938 2,393,396 Miller Jan. 22, 19462,540,811 CObine Feb. 6, 1951

